In oracle HRMS there are so many modules like Core HR, 
Payroll, Self Service HR, Oracle learning management, 
iRecruitment, Time and Labour, Compensation Work bench, 
Oracle Advanced Benefits, Performance Management System 
etc.,
Core HR and System Administrator are the Heart of Oracle 
HRMS.
All basic set ups will do in Core HR with the help of 
System Administrator.

In system administrator we will create all the Users and 
Responsibilities, Flex fields, Profile values etc.,
In core HR we will create Organizations, Locations, Jobs, 
Positions, Grades, Organization Hierarchy, position 
Hierarchy, We will create all the employees also. These are 
the Basic setups in HRMS.